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                                                                   EXHIBIT 10.21

                         THE MIDDLEFIELD BANKING COMPANY
                       EXECUTIVE SURVIVOR INCOME AGREEMENT

         THIS EXECUTIVE SURVIVOR INCOME AGREEMENT (this "Agreement') is made
this 20th day of June , 2003, by and between The Middlefield Banking Company, an
Ohio-chartered, FDIC-insured nonmember bank with its main office in Middlefield,
Ohio (the "Bank"), and Thomas G. Caldwell (the "Executive").

         WHEREAS, to encourage the Executive to remain an employee of the Bank,
the Bank is willing to provide benefits to the Executive's beneficiary(ies) (i)
if the Executive dies before the age of 85 while employed by the Bank, or (ii)
if the Executive dies before age 85 but after having terminated employment on or
after Early Retirement Age, or because of Disability, or within 12 months after
a Change in Control. The Bank will pay the benefits from its general assets, but
only so long as one of its general assets is a life insurance policy on the
Executive's life.

                                    AGREEMENT

         The Executive and the Bank agree as follows:

                                    ARTICLE 1
                                   DEFINITIONS

         Whenever used in this Agreement, the following words and phrases shall
have the meanings specified:

         1.1      "Change in Control" means the definition of Change in Control
specified in any employment or severance agreement existing on the date hereof
or hereafter entered into between the Executive and the Bank. If the Executive
is not a party to an employment or severance agreement containing a definition
of Change in Control, Change in Control means any of the following events occur

         (1)      Merger: Middlefield Banc Corp. ("Middlefield") merges into or
                  consolidates with another corporation, or merges another
                  corporation into Middlefield, and as a result less than a
                  majority of the combined voting power of the resulting
                  corporation immediately after the merger or consolidation is
                  held by persons who were the holders of Middlefield's voting
                  securities immediately before the merger or consolidation. For
                  purposes of this Agreement, the term person means an
                  individual, corporation, partnership, trust, association,
                  joint venture, pool, syndicate, sole proprietorship,
                  unincorporated organization, or other entity,

         (2)      Acquisition of Significant Share Ownership: a report on
                  Schedule 13D, Schedule TO, or another form or schedule (other
                  than Schedule 13G), is filed or is required to be filed under
                  Sections 13(d) or 14(d) of the Securities Exchange Act of
                  1934, if the schedule discloses that the filing person or
                  persons acting in concert has or have become the beneficial
                  owner of 15% or more of a class of Middlefield's voting
                  securities (but this clause (2) shall not apply to beneficial
                  ownership of voting shares held by a subsidiary in a fiduciary
                  capacity),

         (3)      Change in Board Composition: during any period of two
                  consecutive years, individuals who constitute Middlefield's
                  board of directors at the beginning of the two-year period
                  cease for any reason to constitute at least a majority
                  thereof; provided, however, that -- for purposes of this
                  clause (3) -- each director who is first elected by the board
                  (or first nominated by the board for election by stockholders)
                  by a vote of at least two-thirds (2/3) of the directors who
                  were directors at the beginning of the period shall be deemed
                  to have been a director at the beginning of the two-year
                  period, or

         (4)      Sale of Assets: Middlefield sells to a third party
                  substantially all of Middlefield's assets. For purposes of
                  this Agreement, sale of substantially all of Middlefield's
                  assets includes sale of The Middlefield Banking Company.

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         1.2      "Disability" means the Executive suffers a sickness, accident,
or injury which has been determined by the carrier of any individual or group
disability insurance policy covering the Executive, or by the Social Security
Administration, to be a disability rendering the Executive totally and
permanently disabled. The Executive must submit proof to the Bank of the
carrier's or the Social Security Administration's determination upon the request
of the Bank.

         1.3      "Early Retirement Age" means the Executive's 55th birthday,
provided the Executive has at least 10 Years of Service with the Bank on that
date. If the Executive does not have 10 Years of Service with the Bank by the
date of his 55th birthday, the Executive's Early Retirement Age means the date
on which the Executive has 10 Years of Service with the Bank, provided such 10
Years of Service occurs before the Executive reaches age 65. For purposes of
this Agreement, years of service means the total number of twelve-month periods
during which the Executive serves as an employee of the Bank.

         1.4      "Good Reason" means the definition of Good Reason specified in
any employment or severance agreement existing on the date hereof or hereafter
entered into between the Executive and the Bank. If the Executive is not a party
to an employment or severance agreement containing a definition of Good Reason,
Good Reason means the occurrence of any of the events or conditions described in
clauses (a) through (e) hereof without the Executive's express written consent -

                           (a) a material reduction in Executive's title or
                  responsibilities;

                           (b) a reduction in base salary as in effect on the
                  date of a Change in Control;

                           (c) relocation of the Bank's principal executive
                  offices, or requiring the Executive to change his or her
                  principal work location, to any location that is more than 15
                  miles from the location of the Bank's principal executive
                  offices on the date of this Agreement;

                           (d) the failure by the Bank to continue to provide
                  the Executive with compensation and benefits substantially
                  similar to those provided to him or her under any of the
                  employee benefit plans in which the Executive becomes a
                  participant, or the taking of any action by the Bank which
                  would directly or indirectly materially reduce any of such
                  benefits or deprive the Executive of any material fringe
                  benefit enjoyed by him at the time of the Change in Control;
                  or

                           (e) the failure of the Bank to obtain a satisfactory
                  agreement from any successor or assignee of the Bank to assume
                  and agree to perform this Agreement.

         1.5      "Termination for Cause" means the definition of termination
for cause specified in any employment or severance agreement existing on the
date hereof or hereafter entered into between the Executive and the Bank. If the
Executive is not a party to an employment or severance agreement containing a
definition of termination for cause, Termination for Cause means the Bank has
terminated the Executive's employment for any of the following reasons:

                           (a)      Gross negligence or gross neglect of duties;

                           (b)      Commission of a felony or of a gross
                  misdemeanor involving moral turpitude; or

                           (c)      Fraud, disloyalty, or willful violation of
                  any law or significant Bank policy committed in connection
                  with the Executive's employment and resulting in an adverse
                  effect on the Bank.

         1.6      "Termination of Employment" with the Bank means that the
Executive shall have ceased to be employed by the Bank for any reason
whatsoever, excepting a leave of absence approved by the Bank. For purposes of
this Agreement, if there is a dispute over the employment status of the
Executive or the date of termination of the

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Executive's employment, the Bank shall have the sole and absolute right to
decide the dispute, unless a Change in Control shall have occurred.

                                    ARTICLE 2
                             ENTITLEMENT TO BENEFIT

         2.1      Pre-Termination of Employment Survivor Income Benefit. If the
Executive dies in active service to the Bank before reaching age 85, the Bank
shall pay to the Executive's designated beneficiary a survivor income benefit of
$471,741. The survivor income benefit shall be paid in a single lump sum within
90 days after submission of proof of a claim substantiating the Executive's
death.

         2.2      Disability Benefit. If the Executive terminates employment due
to Disability, the Bank shall pay to the Executive's designated beneficiary in a
single lump sum the survivor income benefit described in Section 2.5 provided
the Executive dies before reaching age 85.

         2.3      Change in Control Benefit. If the Executive's employment with
the Bank terminates involuntarily within 12 months after a Change in Control
(excepting Termination for Cause) or in the event the Executive terminates
employment voluntarily for Good Reason within 12 months after such Change in
Control, the Bank shall pay the Executive's designated beneficiary the survivor
income benefit described in Section 2.5 provided the Executive dies before
reaching age 85.

         2.4      Early Retirement Benefit. If the Executive terminates
employment on or after Early Retirement Age, the Bank shall pay to the
Executive's designated beneficiary in a single lump sum the survivor income
benefit described in Section 2.5 following the Executive's death, provided the
Executive's death occurs before the Executive's 85th birthday.

         2.5      Amount of Benefits. If the Employee was no longer employed by
the Bank at the time of death but benefits are nevertheless payable under
Section 2.2, 2.3, or 2.4, the Bank shall pay to the Employee's beneficiary a
survivor income benefit of $471,741. The survivor income benefit shall be paid
in a single lump sum within 90 days after submission of proof of a claim
substantiating the Employee's death. If the Employee dies after reaching age 85,
no survivor income benefits shall be payable under this Agreement.

                                    ARTICLE 3
                                  BENEFICIARIES

         3.1      Beneficiary Designations. The Executive shall designate a
beneficiary by filing a written designation with the Bank. The Executive's
beneficiary designation shall be deemed automatically revoked if the beneficiary
predeceases the Executive or if the Executive names a spouse as beneficiary and
the marriage is subsequently dissolved. If the Executive dies without a valid
beneficiary designation, all payments shall be made to the Executive's estate.

         3.2      Facility of Payment. If a benefit is payable to a minor, to a
person declared incompetent, or to a person incapable of handling the
disposition of his or her property, the Bank may pay such benefit to the
guardian, legal representative, or person having the care or custody of such
minor, incompetent person, or incapable person. The Bank may require proof of
incompetence, minority, or guardianship as it may deem appropriate prior to
distribution of the benefit. Such distribution shall completely discharge the
Bank from all liability with respect to such benefit.

                                    ARTICLE 4
                               GENERAL LIMITATIONS

         4.1      Termination for Cause. Notwithstanding any provision of this
Agreement to the contrary, the Bank shall not pay any benefit under this
Agreement if Termination of Employment is due to the Executive's actions
resulting in Termination for Cause.

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         4.2      Suicide or Misstatement. The Bank shall not pay any benefit
under this Agreement if the Executive commits suicide within three years after
the date of this Agreement. In addition, the Bank shall not pay any benefit
under this Agreement if the Executive has made any material misstatement of fact
on any application or resume provided to the Bank, or on any application for any
benefits provided by the Bank to the Executive.

         4.3      Removal. If the Executive is removed from office or
permanently prohibited from participating in the conduct of the Bank's affairs
by an order issued under Section 8(e)(4) or (g)(1) of the Federal Deposit
Insurance Act, 12 U.S.C. Section 1818(e)(4) or (g)(1), all obligations of the
Bank under this Agreement shall terminate as of the effective date of the order.

         4.4      Default. Notwithstanding any provision of this Agreement to
the contrary, if the Bank is in "default" or "in danger of default" as those
terms are defined in Section 3(x) of the Federal Deposit Insurance Act, 12
U.S.C. 1813(x), all obligations under this Agreement shall terminate.

         4.5      Termination of Participation. The Executive's rights under
this Agreement shall cease if the Executive's employment with the Bank
terminates, except as provided in Section 2.2 (termination because of
Disability), Section 2.3 (termination within 12 months after a Change in
Control), or Section 2.4 (termination because of Early Retirement Age).

                                    ARTICLE 5
                          CLAIMS AND REVIEW PROCEDURES

         5.1      Claims Procedure. A participant or beneficiary ("claimant")
who has not received benefits under the Agreement that he or she believes should
be paid shall make a claim for such benefits as follows:

         5.1.1    Initiation - Written Claim. The claimant initiates a claim by
                  submitting to the Bank a written claim for the benefits.

         5.1.2    Timing of Bank Response. The Bank shall respond to such
                  claimant within 90 days after receiving the claim. If the Bank
                  determines that special circumstances require additional time
                  for processing the claim, the Bank can extend the response
                  period by an additional 90 days by notifying the claimant in
                  writing, prior to the end of the initial 90-day period, that
                  an additional period is required. The notice of extension must
                  set forth the special circumstances and the date by which the
                  Bank expects to render its decision.

         5.1.3    Notice of Decision. If the Bank denies part or all of the
                  claim, the Bank shall notify the claimant in writing of such
                  denial. The Bank shall write the notification in a manner
                  calculated to be understood by the claimant. The notification
                  shall set forth:

                  (a) The specific reasons for the denial;

                  (b) A reference to the specific provisions of the Agreement on
                  which the denial is based;

                  (c) A description of any additional information or material
                  necessary for the claimant to perfect the claim and an
                  explanation of why it is needed;

                  (d) An explanation of the Agreement's review procedures and
                  the time limits applicable to such procedures; and

                  (e) A statement of the claimant's right to bring a civil
                  action under ERISA (Employee Retirement Income Security Act)
                  Section 502(a) following an adverse benefit determination on
                  review.

         5.2      Review Procedure. If the Bank denies part or all of the claim,
the claimant shall have the opportunity for a full and fair review by the Bank
of the denial, as follows:

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         5.2.1    Initiation - Written Request. To initiate the review, the
                  claimant, within 60 days after receiving the Bank's notice of
                  denial, must file with the Bank a written request for review.

         5.2.2    Additional Submissions - Information Access. The claimant
                  shall then have the opportunity to submit written comments,
                  documents, records, and other information relating to the
                  claim. The Bank shall also provide the claimant, upon request
                  and free of charge, reasonable access to, and copies of, all
                  documents, records, and other information relevant (as defined
                  in applicable ERISA regulations) to the claimant's claim for
                  benefits.

         5.2.3    Considerations on Review. In considering the review, the Bank
                  shall take into account all materials and information the
                  claimant submits relating to the claim, without regard to
                  whether such information was submitted or considered in the
                  initial benefit determination.

         5.2.4    Timing of Bank Response. The Bank shall respond in writing to
                  such claimant within 60 days after receiving the request for
                  review. If the Bank determines that special circumstances
                  require additional time for processing the claim, the Bank can
                  extend the response period by an additional 60 days by
                  notifying the claimant in writing, prior to the end of the
                  initial 60-day period, that an additional period is required.
                  The notice of extension must set forth the special
                  circumstances and the date by which the Bank expects to render
                  its decision.

         5.2.5    Notice of Decision. The Bank shall notify the claimant in
                  writing of its decision on review. The Bank shall write the
                  notification in a manner calculated to be understood by the
                  claimant. The notification shall set forth:

                  (a) The specific reasons for the denial;

                  (b) A reference to the specific provisions of the Agreement on
                  which the denial is based;

                  (c) A statement that the claimant is entitled to receive, upon
                  request and free of charge, reasonable access to, and copies
                  of, all documents, records, and other information relevant (as
                  defined in applicable ERISA regulations) to the claimant's
                  claim for benefits; and

                  (d) A statement of the claimant's right to bring a civil
                  action under ERISA Section 502(a).

                                    ARTICLE 6
                                  MISCELLANEOUS

         6.1      Amendments and Termination. The Bank may amend or terminate
this Agreement at any time if, pursuant to legislative, judicial, or regulatory
action, continuation of the Agreement would (i) cause benefits to be taxable to
the Executive prior to actual receipt, or (ii) result in significant financial
penalties or other significantly detrimental ramifications to the Bank (other
than the financial impact of paying the benefits).

         6.2      Binding Effect. This Agreement shall bind the Executive and
the Bank and their beneficiaries, survivors, executors, administrators and
transferees.

         6.3      No Guarantee of Employment. This Agreement is not a contract
for employment. It does not give the Executive the right to remain an employee
of the Bank, nor does it interfere with the Bank's right to discharge the
Executive. The Agreement does not affect the employment status of the Executive,
whether the Executive is an employee at will or otherwise. It also does not
require the Executive to remain an employee nor interfere with the Executive's
right to terminate employment at any time.

         6.4      Non-Transferability. Benefits under this Agreement cannot be
sold, transferred, assigned, pledged, attached or encumbered in any manner.

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         6.5      Successors; Binding Agreement. By an assumption agreement in
form and substance satisfactory to the Executive, the Bank will require any
successor (whether direct or indirect, by purchase, merger, consolidation, or
otherwise) to all or substantially all of the business or assets of the Bank to
expressly assume and agree to perform this Agreement in the same manner and to
the same extent that the Bank would be required to perform this Agreement if no
such succession had occurred.

         6.6      Tax Withholding. The Bank shall withhold any taxes that are
required to be withheld from the benefits provided under this Agreement.

         6.7      Applicable Law. Except to the extent preempted by the laws of
the United States of America, the validity, interpretation, construction, and
performance of this Agreement shall be governed by and construed in accordance
with the laws of the State of Ohio, without giving effect to the principles of
conflict of laws of such state.

         6.8      Unfunded Arrangement. The Executive's beneficiary(ies) are
general unsecured creditors of the Bank for the payment of benefits under this
Agreement. The benefits represent the mere promise by the Bank to pay such
benefits. The rights to benefits are not subject in any manner to anticipation,
alienation, sale, transfer, assignment, pledge, encumbrance, attachment, or
garnishment by creditors. Any insurance on the Executive's life is a general
asset of the Bank to which the Executive and the Executive's beneficiary(ies)
have no preferred or secured claim.

         6.9      Entire Agreement. This Agreement constitutes the entire
agreement between the Bank and the Executive as to the subject matter hereof. No
rights are granted to the Executive's beneficiary by virtue of this Agreement
other than those specifically set forth herein.

         6.10     Administration. The Bank shall have all powers which are
necessary to administer this Agreement, including but not limited to:

                  (a) Interpreting the provisions of the Agreement;

                  (b) Establishing and revising the method of accounting for the
         Agreement;

                  (c) Maintaining a record of benefit payments; and

                  (d) Establishing rules and prescribing any forms necessary or
         desirable to administer the Agreement.

         6.11     Named Fiduciary. For purposes of the Employee Retirement
Income Security Act of 1974, if applicable, the Bank shall be the named
fiduciary and plan administrator under this Agreement. The named fiduciary may
delegate to others certain aspects of the management and operation
responsibilities of the plan including the employment of advisors and the
delegation of ministerial duties to qualified individuals.

         6.12     Severability. If for any reason any provision of this
Agreement is held invalid, such invalidity shall not affect any other provision
of this Agreement not held invalid, and each such other provision shall continue
in full force and effect to the full extent consistent with the law,. If any
provision of this Agreement is held invalid in part, such invalidity shall not
affect the remainder of such provision not held invalid, and the remainder of
such provision, together with all other provisions of this Agreement, shall
continue in full force and effect to the full extent consistent with the law.

         6.13     Headings. The headings of Sections herein are included solely
for convenience of reference and shall not affect the meaning or interpretation
of any provision of this Agreement.

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         6.14     Notices. All notices, requests, demands and other
communications hereunder shall be in writing and shall be deemed to have been
duly given if delivered by hand or mailed, certified or registered mail, return
receipt requested, with postage prepaid, to the following addresses or to such
other address as either party may designate by like notice.

                  (a)      If to the Bank, to:
                           Board of Directors
                           The Middlefield Banking Company
                           15985 East High Street
                           P.O. Box 35
                           Middlefield, Ohio 44062

                  (b)      If to the Executive, to:
                           Thomas G. Caldwell 15985
                           East High Street
                           Middlefield, Ohio  44062

                  and to such other or additional person or persons as either
                  party shall have designated to the other party in writing by
                  like notice.

         IN WITNESS WHEREOF, the Executive and a duly authorized Bank officer
have signed this Agreement.

EXECUTIVE:                                BANK:

                                          THE MIDDLEFIELD BANKING COMPANY

By: _______________________               By: ______________________
                                                   James R. Heslop, II
Thomas G. Caldwell                            Its: EVP/COO
President & CEO

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                             BENEFICIARY DESIGNATION

                         THE MIDDLEFIELD BANKING COMPANY
                       EXECUTIVE SURVIVOR INCOME AGREEMENT

         I designate the following as beneficiary of benefits under this
Agreement payable following my death:

Primary: Tami J. Caldwell

________________________________________________________________________________

Contingent: Brandon G. Caldwell and Brittany M. Caldwell

________________________________________________________________________________

NOTE:    TO NAME A TRUST AS BENEFICIARY, PLEASE PROVIDE THE NAME OF THE
         TRUSTEE(S) AND THE EXACT NAME AND DATE OF THE TRUST AGREEMENT.

         I understand that I may change these beneficiary designations by filing
a new written designation with the Bank. I further understand that the
designations will be automatically revoked if the beneficiary predeceases me, or
if I have named my spouse as beneficiary and our marriage is subsequently
dissolved.

         Signature ___________________________

         Date _______________________________

         By: Thomas G. Caldwell
         Title: President & CEO

         Received by the Bank this ________ day of ___________________, 2003.

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